
Accident Occurence Categories (AOC)
GNATS has equipped with 13 AOC categories that all denote the potential risks
that aircraft, ground vehicles might face during operations and flight. They are as
follows:
Ground Collision (GCOL): A collision between aircraft or ground vehicles during
taxi phase.
Taxiway Excursion (TE): Lateral or longitudinal excursion of an aircraft or ground
vehicle during taxi phase.
Taxiway Incursion (TI): Lateral incursion of aircraft or ground vehicle during taxi
or Longitudinal incursion of an aircraft while landing.
Runway Excursion (RE): Lateral excursion of aircraft or ground vehicle during
takeoff/drive.
Runway Incursion (RI): Collision between aircraft taking off and an
aircraft/ground vehicle crossing the runway.
Wake Turbulence (WAKE): A trailing smaller aircraft flying into the wake vortex
caused by a leading heavier aircraft.
Collision with Obstacles during Takeoff (CTOL): Aircraft not being able to clear
an obstacle (Airport compound wall or building up to 35 ft) during take off.
Runway Undershoot (US): Aircraft landing before the start of the runway due to
steeper than needed glide slope.
Runway Overshoot (OS): Aircraft not able to stop after landing or take off before
runway ends.
Mid Air Collision (MAC): Two aircraft colliding mid air.
Misaligned Landing (ML): When the aircraft landing is not aligned per runway
center line and is drifting away.